Injector



1933. c. H. TRUE 1,921,444

INJECTOR F iled Jan. 29, 1929 2 Sheets-Sheet l a /e 5. 770a INVENTOR.

ATTORNEY.

Aug. 8, 1933. c. H. TRUE 1,921,444

INJECTOR Filed Jan. 29, 1929 2 Sheets-Sheet 2,

(Aer/e a. f/ 7702, INVENTOR.

A TTORNEY.

Patented Aug. 8, 1933 INJECTOR 7 Charles H. True, Chicago,;1ll.,assignor to The -;Superheater Company, New York, N. Y.

Application January 29, 1929. Serial Nb. 335,969

' 10 Claims. (01103 -277) My invention relatesbroadlyto injectors andmore specifically to exhaust steam injectors of the general typedisclosed in United StatesPatent #1342128 granted June 1, 1920 to J.Metcalfe, et a1. Y j

In injectors of this general type, the combining tube of the injector isordinarily provided with an overflow port controlled by 'a plugor flappivotally mounted with respect to the combining tube, said flap beingu'sually held in closed position by gravity and being opened by pressurewithin the combining tube to permit the discharge, through the injectoroverflow; of the initial steam and water admitted to the injectorfor'the establishment of thejet which subsequentlyacts to deliverwaterunder pressure from the injectorf f e In order to insure the highestefficiency in the operation of the injector, it is necessary for thecombining tube flap to seat accurately; and the principal object of thepresent invention is the provision of, a novel form of flap which may bemore readily fitted to; an accurate seat and maintained accuratelyseated than in the forms heretofore known. Another objectofthe inventionis the provision of such aflap construction suitably adapted to massproduction .methods' of manufacture at reduced cost.. Further and moredetailed objects of the'invention, together with the benefitsto bederived fromits' use, will become apparent fromfthe ensuing detaileddescription of a preferred embodiment thereof illustrated in theaccompanying drawings forming a part hereof, in which Fig. 1 is alongitudinal, vertical section taken through an injector 'of the classdescribed; Fig. 2 is a similar section, on an enlarged scale, of thecombining tube as sembly shown in Fig. 1; Fig. 3 isa plan view of Fig.2; Fig. 4 is a section taken on the line 4 1 of Fig. 1; and Fig. 5 is asection taken on the line 55 of Fig. 1.

Referring now to Fig.1, the injector comprises a main casing A formedoftwocastings 1 and 2, the former containing the com-biningtu be 3 andthe delivery nozzle 4 and the latter containing the main low pressuresteam. nozzle..5, supplementary high pressure steam, nozzle 6,

water-cone 7 and secondary low pressure steam 1 nozzle 8. Exhaust steamis admitted through valve. 9, supplementary high pressure steam throughpassage 10, auxiliary live steam-through passage 11, and'water throughthe chamber 12, while'the overflow from ,the combining tube is carriedfrom-the injector through chamber 13 to the overflow outlet 1%. ,Water.under; prespin with respec t to the arm. I

'sureis delivered from the injectorbyiway of the delivery conduit15controlled by the check valve 16, The structure thus far .describedisnot novel, and as its operation is well known to those skilled inth'eart it is not deemed necessary .to describe it in further detailherein.

Referring now tofFigs; .2 and 3, thecombining tube'ass embly comprisesthe main tube3" off'the usual form, which delivers across a small gapl'lin communication with chamber 13' to the entrance of f the deliverynozzle 4. .The upper side of tube '3 is formed with a lateral opening inwhich is seated the fiap IB carried by the longitudinally extending ar'm1 9,jthe latter beingfpiv- I oted at a pointfixed'relative to the nozzleby a transverse pin 201 Preferably the pin". 20 is 'mounted in asuitably bored boss 21 carried by tube 3. In order tominimiZewear, thepin 20 is made of hardened metal and is journaled in a hard metalbushing 22".in boss 2l. Wearbeface. of arm 19, thus preventing rotationof the At its -free end, the arm 19 is bifnrcated lto form fingers19.a-nd 191), each of which is bored .to receive the transverse pin24,and each .of which has a plane lower surface 25 which seats against acooperating surface milled on the upperside :of-fiap 18 to preventpivotal motion of the flap about pin 24, which passes-through thefingers 19a, 19b: and the suitably boredboss26- gage asui-tableupstanding boss 28 on the tube 3, aswi llbe seen-'froml ig 4. As :willreadily-be apparent from: Fig.;- -;2 .fsufficient longitudinal clearancebetween-the boss '28 and the-ends of the rectangular hole in the arm isprovided 1 to permit of the oscillation o'f arm 19 about the "pivot pin"20 without binding upon'boss '28. "The purpose of this boss is'toprovide a lateral bearin'g' support serving to accurately center theflap 18 with respect t0 tube 3 and to prevent lateral 'displacem'ent'incase of wear in pin 20 or the f surface in whichit is journaled.-

The tube 3 is preferably, although not neeesjsarily} provided withtransverse radial bores 29 which serve to connect the delivery end ofthe .bore inthe tube with the overflow chamber 13.

The purpose ofvthese will appear later.

5 being joined at their ends by the transverse bearing surfaces 31 whichare portions of the surface of a cone the axis of which liestransversely of the longitudinal axis of the tube 3.

With the flap 18 formed in this manner, it will be obvious that thebearing surfaces 31 on the flap may be readily formed in a lathe orother tool which revolves the flap about '--an axis vertical as viewedin Fig. 2 and that the bearing surfaces may also be readily formed by asuitable facing tool while the flap is still chucked in such a machine.It will further be evident that the bearing surfaces of the lateralopening in tube 3 designed to receive flap 18 may be formed in a similarmanner, that is, either bya cutting tool acting on the tube 3 which isrevolved about a properly centered axis at right angles to thelongitudinal axis of the tube or by means of a suitably contoured boringor reaming tool revolving about such axis with the tubeheld in a fixedposition. It will further be apparent that the bearing surfaces betweentube 3'and flap 18 may be ground to a perfect fit by the simpleexpedient of oscillating the flap 18 inthe opening in tube 3 before theformer is attachedfto arm 19, in much the same manner as the grinding inof an ordinary poppet valve. With the flap formed in accordance with theinclined plane transverse to the longitudinal axis of the tube, and forthis reason I prefer to provide additional overflow area from the boreof "tube 3 by means of the radial bores 29. These bores-are notessentialto the successful opera tion ofthe injector, and it has been found thatthey do not'affect the operation of'the injector adversely, even thoughthey remain open at all times. l e

While pivotal mounting of the flap with respect to the arm does notrender the device inoperative,- it has been found in practice that apivoted flap. does not ordinarily return squarely to its seat, with theresult that excessive wear occurs on the portions-ofthe bearing surfaceswherethe flap first contacts with the tube. Such wear obviously causestrouble due to'excessive In this connection it is to be noted that theflap does notextend to the delivery end of tube .3, so that-the tube issolid at this point. This construction has an important practicaladvantage, as the inlet end of the delivery, nozzle 4 is subject toexcessive erosiondue to the extreme velocity of the: jet at this point.Ordinarily a renewable tip. 32 is employed at this point, and it hasbeenfound that premature wear of this tip has frequently been caused, in theolder form .of combining tube employing a flap extending to the deliveryend of the tube, by a thin sheet of "water escaping through the jointbetween flap and tube and impinging on the end of the tip.

Obviously in thepresent form ofconstruction,

this cannot occur. g

With the flap fixedly mounted on the arm 19,

it is obvious that a regrinding of the flap which would remove anappreciable amount of metal would, by lowering the flap, prevent itsproper seating unless the position of the flap with re-' junction withan exhaust steam injectorof the horizontal type in which the combiningtube flap is normally held in position by gravity, it will be obviousthat the invention is applicable to other types of injectors, which maybe positioned vertically as Well as horizontally and whichmay employother means for normally urging the combining tube flap to its seat. Theembodiment herein shown is therefore to be considered as illustrativeonly and the invention is to be considered as limited only by the scopeof the appended claims.

I claim: V 1. In an injector, a combining tube having a lateral openingtherein, the perimeter of which comprises conical surfaces, and aclosure for said opening having complementary conical sur faces adaptedto seat against the walls of-said port.

2. In an injector, a combining tube, an over flow chamber, a port insaid tube affording communication between the bore of the combining tubeand the overflow chamber, and meansfor closing said port, said meanscomprising a flap having conical bearing surfaces, and said port havingcomplementary cooperating seating surfaces.

3. In an injector, a combining tube having. a longitudinal conical boretherethrough and -a lateral opening through said tube to said bore, theperimeter of said opening being defined by plane bearing surfaces lyingin a common plane passing through the longitudinal axis of the tube andconnected by bearing surfaces forming portions of the surface of a conethe axis of which is normal to the plane of said first named bearingsurfaces. V

4. As a new article, of manufacture, a flap adapted to close theoverflow opening in an injector combining tube, said flap being in thegeneral form of a' truncated cone and having metrical with respectto acentral axis'through said flap, and plane bearing surfaces connectingthe ends of said conical surfaces, said plane surfaces lying in a planenormal to said axis.

6. Inan injector, a combining tube, an overflow chamber, a port in. saidtube affording communication between the bore, of the com-- biningtubeand the overflow chamber, means for closing said port, said meanscomprisinga pivot fixed with respect to said tube,.an arm movable aboutsaid pivot, the free end of said arm beingprovided with. a finger having,-a planebearing surface thereon, a flap. adapted to seat in said port,said flaphaving a plane surface adapted to abut said first named-surfaceto prevent relative motion between the flap and the arm,"and a pin forremovably securing 9. In aninjector, a combining tube, an overthe flapto the arm with said surfaces in abutting relation.

7. In an injector, a combining tube having a longitudinal conical boretherethrough and a lateral opening through said tube to said bore,

7 the perimeter of said opening being defined by two frusto-conicalbearing surfaces whose axis is normal to the axis of the conical bore,and two plane surfaces at right angles to the axis of the frusto-conicalsurfaces and extending between the two frusto-conical surfaces.

8. In an injector, a combining tube, an. over-V flow chamber, a port insaid tube affording communication between the bore of the combining tubeand the overflow chamber, the perimeter of said port comprising twofrusto-conical surfaces, a closure for said port having complementaryfrusto-conical surfaces, and an arm carrying the closure and pivotallymounted on the tube.

flow chamber, a port in said tube affording communication between thebore of the combining tube and the overflow chamber, the perimeter ofsaid port comprising two frusto-conical surfaces and two planesurfacesextending between them, a closure for the port having acomplementary shape, and an arm carrying the the planeof said firstnamed bearing surfaces.

CHARLES H. TRUE.

